Li Menggang, Han Guanghui, Tian Fenyang, Tao Lu, Fu Linke, Li Lu, Zhou Chenhui, He Lin, Lin Fangxu, Zhang Shipeng, Yang Weiwei, Ke Xiaoxing, Luo Mingchuan, Yu Yongsheng, Xu Bingjun, Guo Shaojun
School of Materials Science and Engineering, Peking University, Beijing, 100871, China.
School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, 150001, China.
Adv Mater. 2024 Dec;36(49):e2412004. doi: 10.1002/adma.202412004. Epub 2024 Oct 23.
Alloying has significantly upgraded the oxygen reduction reaction (ORR) of Pd-based catalysts through regulating the thermodynamics of oxygenated intermediates. However, the unsatisfactory activation ability of Pd-based alloys toward O molecules limits further improvement of ORR kinetics. Herein, the precise synthesis of nanosheet assemblies of spin-polarized PdCu-FeO in-plane heterostructures for drastically activating O molecules and boosting ORR kinetics is reported. It is demonstrated that the deliberate-engineered in-plane heterostructures not only tailor the d-band center of Pd sites with weakened adsorption of oxygenated intermediates but also endow electrophilic Fe sites with strong ability to activate O molecules, which make PdCu-FeO in-plane heterostructures exhibit the highest ORR specific activity among the state-of-art Pd-based catalysts so far. In situ electrochemical spectroscopy and theoretical investigations reveal a tandem catalytic mechanism on PdCu-FeO─Fe sites that initially activate molecular O and generate oxygenated intermediates being transferred to Pd sites to finish the subsequent proton-coupled electron transfer steps.
通过调节含氧中间体的热力学，合金化显著提升了钯基催化剂的氧还原反应（ORR）性能。然而，钯基合金对O分子的活化能力欠佳，限制了ORR动力学的进一步改善。在此，我们报道了自旋极化的PdCu-FeO面内异质结构纳米片组装体的精确合成，其可大幅活化O分子并提升ORR动力学。结果表明，精心设计的面内异质结构不仅能调整Pd位点的d带中心，减弱含氧中间体的吸附，还能赋予亲电的Fe位点强大的O分子活化能力，这使得PdCu-FeO面内异质结构在目前最先进的钯基催化剂中展现出最高的ORR比活性。原位电化学光谱和理论研究揭示了PdCu-FeO上Fe位点的串联催化机制，即首先活化分子O并生成含氧中间体，然后将其转移至Pd位点以完成后续的质子耦合电子转移步骤。
